1. Technical Field
The present invention relates to a surface-mount type piezoelectric device used in communication equipment and an electronic apparatus.
2. Related Art
In recent years, downsizing of apparatuses has been rapidly progressed due to demand of improving portability of electronic apparatuses and communication equipment. Therefore, a piezoelectric device as typified by a crystal oscillator used for those apparatuses is required to be reduced in size and height.
As a piezoelectric device reduced in size and height, a crystal oscillator with a structure shown in JP-A-2005-117188 (refer to FIGS. 1, 6, and 7) has been known. This crystal oscillator will be described with reference to FIGS. 3A and 3B. FIG. 3A is a schematic sectional view of the crystal oscillator, and FIG. 3B is a bottom view of the crystal oscillator.
A crystal oscillator 50 has a crystal resonator package 60 having a crystal resonator element 61 therein. On a bottom surface of the crystal resonator package 60, an IC component 62 including an IC chip is mounted and a connection terminal 64 of the crystal resonator package 60 is coupled with a terminal 63 of the IC component 62. Further, as shown in FIG. 3B, an electrode 66 made of a conductive adhesive is formed to be extended to reach a bottom surface of the IC component 62 from the connection terminal 64 located outward from an outer frame of the IC component 62 through a side surface of the IC component 62. Accordingly, conductivity between the connection terminal 64 formed on the bottom surface of the crystal resonator package 60 and the bottom surface of the IC component 62 is ensured. The electrode on the bottom surface of the IC component 62 is used as an external electrode for an external connection with a circuit substrate or the like.
However, in the structure of the crystal oscillator 50 in related art mentioned above, when the crystal oscillator 50 is reduced in size and the size of the IC component 62 is relatively large compared to that of the crystal resonator package 60, it is conceivable that an area for the connection terminal 64 on the bottom surface of the crystal resonator package 60 and located outward from the outer frame of the IC component 62 becomes small, making a connection with the connection terminal 64 by a conductive adhesive difficult.
Further, since the electrode 66 is made of a conductive adhesive, running off of the conductive adhesive from the outer frame of the crystal oscillator 50 and difficulty in forming a shape of an external electrode with high accuracy are considered as issues.